Petroleum binder oil from catalytic cracking



Feb. 20, 1968 G. P. HAMNER 3,369,996

PETROLEUM BINDER OIL FROM CATALYTIC CRACKING Filed May 20, 1965 GASESPRODUCT 3\ ,/FRACTIQNATOR l8 [CATALYTIC CRACKING ZONE /l 12 2 FLASH/DISTILLATION 4\ ZONE HOPPER 'L 2s STEAM 26 ASPHALT Glen Porter Humnermm PATENT ATTORNEY United States Patent ()fiiee 3,3693% Patented Feb.20, 1968 3,369,996 PETROLEUM BINDER OIL FROM CATALYTIC CRACKING GlenPorter Hamner, Baton Rouge, La., assignor to Esso Research andEngineering Company, a corporation of Delaware Filed May 20, 1965, Ser.No. 457,318 7 Claims. (Cl. 208120) This invention relates to an improvedprocess for the preparation of carbonaceous binders suitable for use incarbon or graphite electrodes. More particularly, this invention relatesto an improved process for the preparation of carbonaceous binders fromcatalytic fractions of coal tar, petroleum, or shale oil for use incarbon or graphite electrodes which are equal to or superior to those ofthe prior art.

Heretofore, carbon or graphite electrodes have generally been producedfrom a suitable hard carbonaceous material, usually calcined coke.However, inasmuch as the coke has no natural adhesiveness, it must bebound together in the desired shape or configuration with a suitablycompatible material. Hence, when producing electrodes, the coke isusually ground, mixed with a binder material, molded, and subsequentlybaked so as to carbonize said binder material. It is well known in theart relative to electrode production that the nature and quality of thebinder material used is extremely critical. For example, if pitch isemployed as the binder material, such pitch must fall within arelatively narrow range of specifications in order to be suitable as abinder material.

It is also well known that the specifications of these binder materialsare empirical in nature. A low hydrogen to carbon atomic ratio isrequired in order to minimize the development of porosity during theelectrode operation. In addition, a high coking value is necessary. Thecoking value is a measure of the amount of coke residue produced by apitch when decomposed by heating at 1200 F. for four hours. A softeningpoint of 180 F. to 320 F. is also required. Softening points of lessthan 180 F. do not provide a sufiicient binding of the fabricatedelectrode and the formations tend to loose shape in the pre-calcinationwarm-up technique utilized. On the other hand, the materials possessingextremely high softening points, i.e. above 320 F., are not amenable tomixing with coke particles, they do not have enough plasticity foreffective molding operation, and also possess other inherentdisadvantageous characteristocs. Hence, the softening is preferablywithin the range of temperatures of from 180 to 320 F. The pitchessoftening in the lower portion of this range are designated as softpitches, and those softening in the upper portion of said range aredesignated as hard pitches.

Inasmuch as the Conradson carbon value is a measure of cokingproperties, it is manifest that a high Conradson carbon content, at anaccepted softening point, is desirable. Hence, the relationship betweenConradson carbon and softening point values become a criterion inevaluating the pitch product.

In the past, coal tar pitch has been substantially exclusively employedas the binder material in the manufacture of carbon products, e.g.carbon electrodes, inasmuch as petroleum pitches generally did not meetthe above specifications, for example, did not contain appreciablebenzene and quinoline insolubles and, hence, were generally undesirableas binders. The petroleum pitches were found undesirable because of aplurality of reasons, such as, for example, the electrodes madetherefrom were of uneven mechanical strength and varied in electricalconductivity. While highly aromatic tars resulting from crackingprocesses appeared potentially attractive, such tars failed to result ina production of a satisfactory pitch which was acceptable as a binder.For example, if the coking value and content of benzene and quinolineinsoluble matter of the resulting binders were high enough to satisfythe desired specifications, then the softening point was found to be toohigh. Conversely, if the softening point was in the correct range, thenthe coking value and content of benzene and quinoline insoluble matterwas too low. Further, white some processes in the prior art relating topetroleum pitches resulting in a binder material would satisfy thedesired specifications, such processes had serious inherentdisadvantages which made them commercially unattractive. One suchdisadvantage was the tendency to form insoluble fractions duringprocessing which settled from the product in storage and/ or causedfouling in the process facilities utilized.

With regard to coal tar, as hereinbefore mentioned, pitch prepared fromsuch coal tar has been almost universally employed as the bindermaterial in the manufacture of carbon products. It thus follows,naturaly, that it is also desired to provide a process which producessuch binder material in yields higher than those heretofore realized,while maintaining standards equal to or better than the specificationsset forth.

It is an object of the present invention, therefore, to provide andimprove binder material in yields superior to those heretofore realized.It is another object of the present invention to provide a process whichwill produce a superior binder material from coal tar or petroleumfractions in yields higher than those heretofore realized. It is stillanother object of this invention to provide a binder material frompetroleum residue which will simulate the physical properties of a coaltar pitch binder. It is a further object of this invention to provide aprocess for the production of highly desirable binders from petroleumresidues without incurring the disadvantages heretofore known in therelated art. It is also an object of the present invention to provide acommercially feasible, continuous process for converting coal andpetroleum tars to valuable electrode binder pitches. Other objects andadvantages will become apparent from discussion and disclosure whichfollow.

The sole figure is a schematic flow diagram illustrating a preferredmethod for practicing the process in a continuous manner.

In accordance with the present invention, it has been found that theabove objects can be accomplished by subjecting a suitable feedstock,e.g. mid-boiling fractions, i.e. gas oil (SOD-1050" F.) from crudepetroleum, to catalytic cracking with a molecular sieve catalyst or ablend of said molecular sieve catalyst with silica, silica-alumina,alumina, activated carbon a high surface area binder, or the like. Saidcatalytic cracking is effected at a temperature in the range of 7501050F. and under pressures of from 0 to 500 p.s.i.g. A catalyst to petroleumfeed ratio of about 1:40 is employed and the reaction is generallyefiected at flow rates of from 1 to 14 w./hr./w.

In accordance with the invention, it has also been found that anaddition of a suitable carbonaceous material, e.g. carbon black, to thebinder oil fraction, which has been preferably stripped to a softeningpoint of 180 F. or more, may be made in order to advantageously controlthe fluidity of the binder oil, e.g. when employed inSoderberg-electrode production. Accordingly, it is contemplated to addsuch carbonaceous material in amounts ranging from about 2 to 10 wt.percent, preferably 2.5 to 5 wt. percent, based on the total binder oilfraction.

A petroleum bind'er oil produced in accordance with the process of thepresent invention is found to have a composition of desired componentssimilar to those of coal tar pitch. Prebaked electrodes made from apetroleum binder oil having a minimum concentration of benzene andquinoline insolubles are found advantageously to equal to the standardcoal tar products of the prior art.

More specifically, the processing sequence of the present inventioninvolves treating the gas oil fractions of crude petroleum in thefollowing manner:

FEED INSPECTIONS (1) Mid-boiling fractions, i.e. gas oil (5001l50 F.)from crude petroleum is introduced to a one-pass catalytic cracking inwhich the napthalenes and isoparaifins contained therein are largelyconverted to lighter boiling products, including gasoline and heatingoils. Trace impurities such as nitrogen, sulfur, and metals may bereduced in this step through carbon deposition on the cracking catalyst.

(2) The mid-boiling fraction (590650 F.) from step (1) may, if desired,be sent to steam cracking at temperatures of about 1100 F. to 1500 F. inwhich the linear chain paraffins are substantially converted to olefinsand diolefins which are preferred in the utilization as basic chemicalraw materials.

(3) The higher boiling aromatic and condensation products (850 F.+) fromstep (1) are recovered as a catalytically-cracked material. Thismaterial is subsequently stripped to a softening point temperature of180 F. or above. While said stripping operation is being effected it maybe desirable to add a carbonaceous material as disclosed above.

The charge stock for the process of this invention may be any petroleumcrude oil which ordinarily would be used for the preparation ofpetroleum products. The process is particularly valuable for thepreparation of such products from naphthenic base crude oils such asthose obtained from Southern Louisiana fields. Other charged stocksespecially advantageous for use in the process of this invention includeresidual gas oils from propane/ butane deasphalted vacuum residuum,thermal gas oils, coal tar oils, and shale oils of equivalent boilingrange previously disclosed.

The actual practice of this invention may be understood more readily byreference to FIGURE 1 attached herewith. In FIGURE 1, a topped crude oilfrom an atmospheric tower, not shown, in which for example, a furnaceoil and lighter fractions have been removed, is delivered through lineto vacuum tower 1. In accordance with the invention, the top crude oilintroduced into tower 1 has a boiling point of above 600 F. and,preferably, a boiling range of 650 to 1150 F. Vacuum tower 1 is operatedat a flash temperature corrected to atmospheric pressure above about 900F., and may range up to a corrected equivalent temperature of about 1300F. A distillate gas oil, that is, a heavy virgin gas oil, suitable foruse as a catalytic cracking charge is discharged through line 12 fromthe top of vacuum tower 1 and a bottoms fraction containing virgin heavyresiduum is delivered via line 14 from the bottom of the vacuum tower 1.Ordinarily steam is injected to a line into the bottoms of the vacuumtower to aid in the stripping of volatile components from the bottomsfraction, i.e. high a'sphaltenes or asphalt which are removed from thebottom of tower 1. Thus, in accordance with the invention the vacuumdistillation effected in tower 1 may be defined as one adapted to removea distillate, i.e., the heavy gas oil fraction having a boiling range of500 to 1350 F. and preferably 650 to 1150 F.

The heavy virgin gas oil removed from the top of tower 1 via line 12 isintroduced into catalytic cracking zone 2. The operation per seconducted in zone 2 constitutes a conventional type of once-throughcatalytic cracking operation. Hence, the catalytic cracking mayconstitute the fixed-bed type of. cracking, moving bed type of crackingor fluidized catalytic cracking. In accordance with the presentinvention, the cracking catalyst system employed in said catalyticcracking zone consists essentially of a molecular sieve catalyst, or ablend of said molecular sieve catalyst with silica, silica-alumina,alumina activated carbon or a high surface area binder. Accordingly,cracking conditions require maintenance of temperatures in the range ofabout 650 to 1150" F. and preferably 750 to 1050 F. and at pressuresranging from O p.s.i.g. to about 500 p.s.i.g. The catalytic crackingcatalyst is employed in a catalyst to heavy virgin gas oil ratio of from1:1 to 40:1 and preferably 4:1 to 20:1. The flow rate through saidcatalytic cracking zone is maintained at a rate of from 1 to 14w./hr./w. preferably 1 to 4 w./hr./w. The catalytic agent employed isregenerated intermittently or continuously in order to restore ormaintain the activity of the catalyst. The typical operation, catalyticcracking of the heavy virgin gas oil feed results in conversion of about30 to 60% boiling in the gasoline boiling range and about 70 to togasoline and lighter.

More specifically, the cracking catalysts which are employed inaccordance with the process of this invention consists essentially ofcrystalline alumino-silicate zeolites, commonly referred to as molecularsieves or crystalline alumino-silicate zeolites blended with silica,silica-alumina, alumina activated carbon or a high surface area binder.Such crystalline alumino-silicate zeolite are well known in the art andthey are characterized by their highly ordered crystalline structure anduniformly dimensioned pores. They are distinguishable from each other onthe basis of composition, crystal structure, adsorption properties, andthe like. The term molecular sieves is derived from the ability of thesezeolite materials to selectively adsorb molecules on the basis of theirsize and form. The various types of molecular sieves may be classifiedaccording to the size of the molecules which will be rejected (i.e. notadsorbed) by a particular sieve. A number of these zeolite materials aredescribed, for example, in U.S. Patent 3,013,982, wherein they arecharacterized by their composition and X-ray diffractioncharacteristics.

In general, the crystalline alumino-silicate zeolites within the purviewof the present invention may be represented by the following formula,expressed in terms of moles:

wherein M is selected from the group consisting of metal cations andhydrogen, n is its valence, and X-is a number from about 1.5 to about12. The value of X will vary with the particular zeolite in question.Among the wellknown natural zeolites are mordenite, faujasite,chabazite, gmelinite, analcite, erionite, etc. Such zeolites differ instructure, composition, and particularly in the ratio of silica toalumina contained in the crystal lattice structure; e.g. mordenite,having a ratio of about 8 to about 12; faujasite, having the ratio ofabout 2.5 to about 7; etc. Similarly, the various types of syntheticcrystalline zeolites, e.g. faujasite, mordenite, etc., will also havevarying silica to alumina ratios depending upon such variables ascompositions of crystallization mixture, reaction conditions, etc. US.Patent Nos. 3,013,982-86 describe a number of synthetic zeolites,designated therein as zeolites A, D, L, R, S, T, X and Y.

The processes for producing such crystalline synthetic zeolites are alsowell known in the art. Typically, they involve crystallization fromreaction mixtures containing: A1 0 as sodium aluminate, alumina sol andthe like; SiO as sodium silicate and/ or silica gel and/ or silica sol;alkali metal oxide, e.g. sodium hydroxide, either free or in combinationwith the above components; and water. Careful control is kept over thealkali metal oxide concentration of the mixture, the proportions ofsilica to alumina in alkali metal oxide to silica, the crystallizationperiod, etc., to obtain the desired product.

The zeolite which will be most preferred in the present invention is thesynthetic faujasite variety, wherein X in the above formula is about 2.5to 7, preferably 3 to 6, most preferably 4 to 5.5. Itwill usually havean average pore diameter of about 6 to 15, preferably 8 to 13, A. Aconventional scheme for preparing synthetic sodium faujasite is asfollows:

Colloidal silica or silica hydrosol is mixed with a solution of sodiumhydroxide and sodium aluminate at ambient temperature. Suitable reactantmolar ratios fall within the following ranges: Na O/SiO 0.28 to 0.80;SiO Al O 4 to 40; H O/Na O, 15 to 60. The reaction mixture is preferablyallowed to digest at ambient temperature for up to 40 hours or more,preferably 1 to 15 hours, or cooled to below about 80 F., in order toaid crystallization, and then heated to and held at about 180 to 250 F.,e.g. 200 to 220 F., for a sufficient period to crystallize the productand to achieve maximum crystallinity, e.g. 24 to 200 hours or more,typically 50 to 100 hours. A crystalline hydrated sodiumalumino-silicate zeolite having a faujasite structure is the separatedfrom the aqueous mother liquor by decantation or filtration, washed, anddried to recover a crystalline product. It is then calcined attemperatures up to about 1000 F. in order to remove the water ofhydration and thereby form interstitial channels which confer adsorptiveand catalytic properties.

The crystalline alumino-silicate zeolites which are used as catalyticagents in the cracking step of the instant process must be subjected tocation exchange to reduce their alkali metal oxide (e.g. Na O) contentto less than about 10 wt. percent, preferably less than about 6 wt.percent since alkali metal oxides do not effectively promote the desiredcracking reactions. Accordingly, the alkali metal oxide content iscustomarily reduced by ion exchange treatment with solutions of ammoniumsalts, or salts of metals in Groups I to VIII or the rare earth metals,preferably metals in Groups II, III, IV, V, V-I-B, VII-B, VIII and rareearth metals. Specific examples of suitable metals include magnesium,calcium, boron aluminum, nickel, cobalt, yttrium, cerium, platinum,iron, copper, zinc, manganese, palladium and lanthanum. The alkalineearth metals will be preferred, with magnesium being particularlypreferred. The ion exchange can be simply accomplished by slurrying thezeolite product with an aqueous solution of the desired cation attemperatures of about 60 to 180 F. to replace the alkali metal, andwashing the resulting base-exchange material free of soluble ion priorto drying. Suitable salt solutions include, for example, magnesiumsulfate, calcium chloride, barium chloride, iron sulfate, ammoniumhydroxide, ammonium chloride, etc. Magnesium ion has been found to beespecially valuable informing a superior cracking catalyst.

With regard to the use of crystalline zeolites as catalytic crackingcatalysts, it has been found that the extremely fine size crystals whichare usually produced in their manufacture have generally provedunsuitable in moving or fluidized bed operations because of excessivecarryover losses. Additionally, these crystalline zeolites arefrequently unsuitable for direct use as catalysts because 6 of theirextremely high activities which often lead to over conversion andundesirable product selectivity. Accordingly, it has been discoveredthat an improved form of crystalline alumino-silicate zeolite, which isusitable for moving or fluidized bed operations can be produced bydistributing the crystalline zeolite throughout a siliceous gel or cogelmatrix. The terms gel and cogel as used herein are intended to includegelatinous precipitates, hydrosols, or hydrogels of silica' and/oradmixtures of silica and one or more oxides of metals selected fromGroups II-A, III-A and IV-B of the Periodic Table, e.g. alumina,magnesia, zirconia, titania, etc. The silica content of the gel mayrange from about 55 to wt. percent. The term siliceous as used herein isthus intended to include silica per so as well as silica in combinationwith one or more of the above metal oxides. Silica-alumina cogel isespecially preferred. The resulting composite,

which consists of crystalline zeolite distributed throughout a siliceousgel or cogel matrix, has been found to exhibit improved catalyticselectivity, stability and fluidization properties.

A relatively simple means of incorporating the crystallinealumino-silicate zeolite into the siliceous matrix is to add pre-formedzeolite crystals to a suitable hydrogel such as silica-alumina hydrogel,and homogenize the resulting mixture by passage through a blendingapparatus, such as a colloid mill, ball mill, and the like. Thehomogenized slurry is then formed into particles of a size range desiredfor fluidized bed operations. This may be conveniently accomplished byany rapid drying technique, such as spray drying, although other methodsmay be employed. For the catalytic cracking purposes, of this invention,the final composite catalyst will typically contain about 4 to 12 wt.percent crystalline zeolite. The water content of the hydrogel orgelatinous precipitate before spray drying is adjusted to within therange of about 88 to 96 wt. percent, and the crystalline aluminosilicatezeolite is added in sufficient amount to produce the aforementionedcompositions. The resulting slurry is mixed well and is then formed intofluidizable particles by spray drying.

In accordance with the invention, the alumino-silicate compositionutilizable herein may be suitably blended with other materials havingcatalytic properties for the treatment of petroleum oils. Suitablematerials include, for example, silica or silica and one or moremetallic oxides, such as, alumina, magnesia, zirconia, beryllia, boria,and the like. These catalysts are generally prepared from silicahydrogel or hydrosol, then mixed with a suitable metallic oxide,preferably alumina. A standard catalytic agent is one containing about13% alumina and 87% silica.

In addition to foregoing co-agents, activated carbon may also be blendedwith the alumina-silicate catalytic agents of this invention.

The blends of co-catalytic agents with the aluminosilicates of thisinvention may be used in powdered, granula, or molded state formed intospheres or pellets or finely divided particles having a particle size of2 to 500 mesh. The catalytic blend is then preferably pre-calcined in aninert atmosphere near the temperature contemplated for cracking but maybe calcined initially during use in the cracking operation. Generallythe catalyst blend is dry between F. and 600 F. and thereafter calcinedin air or in inert atmosphere of nitrogen, hydrogen, helium, flue gas orother inert gas at temperatures ranging from about 500 F. to about 1500F. for periods of time ranging from 1 to 48 hours or more.

Referring again to FIGURE 1, the products of the once-through catalyticcracking operation are removed from the catalytic cracking zone 2through line 16 for introduction to a product fractionator 3 which mayconstitute one or more distillation zones. Distillation zone may beoperated to permit removal of like portions of the catalytically crackedproduct through an overhead line; to permit the removal of gasoline,furnace oil, and the like through one or more side stream controls, and;to permit heavier fractions of the catalytically cracked products, forexample, light catalytic cycle oil (LCCO) and heavy catalytic cycle oil(HCCO) from the lower portions of the said fractionator 3. Thus, a lightcatalytic cycle oil (LCCO) fraction boiling above about 400 F. andboiling up to about 600 F. may be removed from a lower side streamWithdrawal 18. Similarly, a heavy catalytic cycle oil (HCCO) fractionboiling above about 590 F. and boiling up to about 850 F. may be removedfrom a lower side stream withdrawal 20. In accordance with the presentinvention, heavy residual fractions of the catalytically crackedproducts are removed from the bottom of fractionator through line 22.The bottoms withdrawal stream 22 will include hydrocarbons boiling about850 F. and boiling up to about 1200 F. or higher. In the event that apowdered catalyst is employed in the catalytic cracking zone 2, somecatalysts will be entrained in the bottoms withdrawal. In this case, theproduct of line 22 may be subjected to a clarification or filtrationoperation in order to segregate the hydrocarbons from crackingcatalysts, and the product of this operation is commonly calledclarified oil.

The bottoms withdrawal stream, in line 22 from product fractionator 3,comprising catalytically cracked product is delivered through said line22 into an atmospheric flash distillation tower 4. Fractions boiling at900 F. and lower temperatures are removed as distillate products fromtower 4 via line 24 and a petroleum binder oil product is discharged asa bottoms product through line 26. The flash temperature in tower 4 iscontrolled such that the overhead vapors range from about 800 F. up toabout 950 F. The maximum flash temperature in the tower is critical inaccordance with this invention since it is employed to obtain thedesired specific softening point, e.g. 180 F. or more, in the finalbinder oil product.

In an embodiment of the present process, the carbonaceous material maybe added to the binder oil fraction for controlling the fludity of thebinder oil when used for Soderberg-type electrode production, e.g. inamounts of from 2 to 10 wt. percent, preferably 2.5 to 5 wt. percent,based on the total binder oil fraction. Accordingly, said carbonaceousmaterial may be added prior to or subsequent to subjection to vacuumdistillation in the zone 4. As illustrated in FIGURE 1 said carbonaceousmaterial is added from hopper or bin 5 via line 28 into the final binderoil product. The carbonaceous materials which find utility in themanufacture of the petroleum binder oil compositions of this inventionare those carbonaceous materials which are amorphous in nature.Representative carbonaceous materials can be employed out of thosematerials which are found in their natural state or derived frommaterial wherein carbon is constituent as in coal, petroleum, gas or oiland asphalt materials. Carbon obtained artifically, in varying degreesof purity, as carbon black, lamp black, activated carbon, charcoal andcoke are suitable sources which can be employed to obtain carbon in themanufacture of the catalytic compositions of this invention.

As mentioned, the attractive advantage of this invention is increasedbinder oil yields and the increased Conradson carbon values for binderoils of given softening points as compared with binder oils produced byother processes of the art. The production of a marked increase inbenzene/quinoline insoluble components Without the formation of coke isalso a unique feature of the process. As employed herein, the ConradsonCarbon value is defined as wt. percent carbon residue after evaporationby destructive distillation (ASTM D189 Procedure). The softening pointis defined as that temperature at which a steel ball drops through aspecific quantity of sample suspended in glycerine (ASTM D36-62T).

In order to illustrate the unique features and advantages of the processhereinbefore described, references made to exemplary data attained inevaluating the process of this invention.

Example I Part APreparati0n of Sodium Form of CrystallineAlumina-Silicate Ze0lite.-The sodium form of a crystallinealuminosilicate zeolite having a silica to alumina mole ratio of about5.1 was prepared by the following typical procedure.

A solution of 30.0 kilograms of NaOH and 8.5 kilograms of sodiumaluminate in 107.5 liters of water was added with stirring to 193.0kilograms of low soda Ludox (30 wt. percent silica hydrosol supplied byE. I. duPont de Nemours & Co.) contained in a 200 gallon steam jacketedvessel. Mixing was conducted at ambient temperatures. Stirring wascontinued until the mixture was homogeneous. The mixture was then heatedto 210 to 215 F. and maintained at said temperature for 5 /2 days toeifect crystallization. The crystals were removed from the liquor byfiltration and water washed until the wash water showed a pH of 9.0 to9.5. On drying, the crystalline alumino-silicate analyzed 13.9% Na O,64.0% SiO and 21.2% A1 0 On a mole basis, this corresponds to: 1.08 NaO:1.0 Al O :5.l SiO The zeolite exhibited a typical faujasite structureas determined by X-ray analysis.

Part B-Preparati0n 0 Magnesium Form 0 Crystalline Alumina-SilicateZe0lite.T-he above sodium form of crystalline alumino-silicate zeolitewas converted to the magnesium form by the following procedure.

Twenty kilograms of the dried sodium-zeolite were added to 50 gallons ofa 6% by weight solution of MgSO The slurry was stirred at ambienttemperatures (70 to F.) for 3 hours. Stirring was stopped, the solidswere allowed to settle, and the supernatant liquor was removed bydecantation. This exchange procedure was repeated two more times usingfresh 6% MgSO solutions each time. The solids were finally water washeduntil the wash water gave a negative test for sulfates with bariumchloride. On analysis the zeolite contained 5% MgO and 3.85% Na O.

Part CPreparati0n of Magnesium Form of Catalyst in Siliceous Matrix.-Theabove magnesium form of the crystalline alumino-silicate zeolite wasmodified by slurrying the above-described magnesium form of the zeolitein an unwashed silica-alumina hydrogel containing 25 wt. percent aluminawhich was prepared by a procedure similar to that described above. Aftermixing and spray drying at about 600 F., the product was slurried in a1.2 wt. percent ammonium carbonate solution in an amount sufficient toyield 13.5 equivalents of ammonium ion per equivalent of sodium ion inthe zeolite. After stirring for 1 hour, the slurry was filtered, washedwith water, and the ammonium-exchange treatment was repeated with freshammonium carbonate solution, filtered, and rinsed on the filter. Thefilter cake was then reslurried in fresh magnesium nitrate solutioncontaining 1.4 wt. percent salt. The amount of magnesium nitratesolution used provided 10 equivalents of magnesium ions per sodium andammonium ion in the zeolite. After stirring for about 1 hour, the slurrywas filtered, washed with water, and water, and dried. The finalcatalyst comprised 5 wt. percent magnesium form zeolite embedded in wt.percent EXAMPLE II.-Catalytic Cracking The catalyst of Example Ireferred to above was initially calcined at 1000 F. and then steamed at1400 F. and 0 p.s.i.g. pressure for 16 hours. The calcined catalyst wasthen employed in a batchwise fluidized bed type cracking operation. Thefeedstock was a gas oil having a boiling range of 600800 F., a sulfurcontent of 1.14 wt. percent, and a gravity of 269 API. The run wasconducted at atmospheric pressure and 960 F., using a 3- minute cycletime. The results of this run with the above catalyst are summarized inTable I.

TABLE I.CATALYTIC CRACKING OF 600800 F. VIRGIN GAS OIL [Temperature, 960F.; pressure, atm.; cycle time, 3 min] Catalyst description andpreparation Preformed Mg-zeolite embedded in unwashed 75% silica- 25%alumina hydrogel; spray dried; ammonium exchanged; magnesium exchanged;washed and dried. Conversion to 430 F., wt. percent 77. Carbon, wt.percent 7. Ca-Dry Gas, wt. percent- 10. Ct to 430 F., wt. percent 50.

As shown in the above table, the catalyst of the present inventiondemonstrated more than twice the activity of a conventional crackingcatalyst. The catalyst of the invention is shown to be substantiallysuperior for catalytic cracking of gas oil feeds to naphtha product. Itis to be noted that, in this example, the silica and alumina contents ofthe hydrogel matrix in the catalyst of the present invention was thesame as that of a standard silica-alumina cracking catalyst.

Example III This example presents a comparison of a binder containing noextraneous carbonaceous material, i.e. a straight binder with a bindercontaining 2.5 Wt. percent of a carbonaceous material, i.e. carbonblack.

ELECTRODE BINDER OIL INSPECTIONS It is obvious from the comparative datathat addition of suitable amounts of carbonaceous material has abeneficial efiect on the physical properties of a binder oil.

Example IV This example serves to illustrate the excellent electrodeswhich may be prepared by utilizing the binder oils of this invention.

ELECTRODE EVALUATION-PREBAKED Source Coal Tar 1 Catalytic PetroleumBinder Electrode Mix:

Percent Binder 23 23 Delayed Coke...- 77 77 Density 1.66 1. 64 BakedElectrode:

Percent Shrinkage 1.82 -1. 22 Percent Wt. Loss. 9. 3 8. 5 Density 1.49 1. 50 Compressive Strength. 7,000 8, 200 Resistivity 2. 77 2. 73

1 Coal tar inspections: Softening point of 212 F., Conradson Carboncontlent of 53% and contained 28% benzene insolubles and 9.1% quinolineinso ubles.

ELECTRODE EVALUATION.SODERBERG TYPE Percent From the foregoing data itis readily apparent that the results issuing from the practice of thepresent invention differ with conventional practice, not in degree, butin kind. Inspections show extreme differences in softening points and inConradson Carbon values as Well as in benzene and quinoline insolubles.Further, the electrodes made from the binder materials Were then theinstant invention equal and surpass minimum quality specifications.

It is to be understood that this invention is not limited to thespecific examples which have been offered merely as illustrations andthat modifications may be made without departing from the spirit of theinvention.

What is claimed is:

l. A process for the preparation of binder oils from a feed consistingessentially of a distillate gas oil fraction having a boiling range ofabout 650 to 1150" R, which consists essentially of, catalyticallycracking said feed in a one-pass catalytic cracking zone, saidcatalytically cracking zone containing an alumino-silicate zeolitehaving an average pore diameter of about 6 to 15 A and catalyticallycracking said feed at a temperature of about 650 to 1150 F., a pressureof from 0 to 500 p.s.i.g., catalyst to gas oil ratio of about 1:1 to40:1 and at a flow rate of 1 to 14 w./hr./w., distilling thecatalytically cracked resulting product to separate lighter fractionsfrom a bottoms fraction boiling above about 850 F. passing said bottomsfraction to a distillation zone and therein stripping said bottoms ofsubstantially all of the volatile products boiling over about 900 F. toproduce a binder oil product.

2. The process of claim 1 in which said zeolite has been base-exchangedwith a cation selected from the group consisting of hydrogen containingcations and cations of metals in Groups II, III, IV, V, VIB, VII-B,-

VIII and the rare earth metals.

3. The process of claim 1 wherein said alumino-silicate zeolite has beenbase-exchanged with magnesium.

4. A process for the preparation of binder oils from petroleum crude oilwhich consists essentially of flashing a topped crude oil under vacuumand at flash temperature above about 900 F. (atmospheric), recovering aproduct consisting essentially of a distillate gas oil fraction having aboiling range of about 650 to 1150 F., catalytically cracking said gasoil fraction in a one-pass catalytic cracking zone, said catalyticallycracking zone containing an alumino-silicate zeolite having an averagepore diameter .of about 8 to 13 A and catalytically cracking said gasoil fraction at a temperature of about 750 to 1050 F., a pressure offrom 0 to 500 p.s.i.g., a catalyst to gas oil ratio of 4:1 to 20.1 andat a flow rate of 1 to 4 w./hr./w., adding from about 2 to 10 Wt.percent of a carbon black material prior to or after distilling thecatalytically cracked resulting product to separate lighter fractionsfrom a bottoms fraction boiling above about 850 F. passing said bottomsfraction to a distillation zone and therein stripping said bottoms ofsubstantially all of the volatile products boiling over about 900 F. toproduce a binder oil product.

5. The process of claim 4 in which said alumnio-silicate zeolite hasbeen base-exchanged with a cation selected Baked Electrode Data, kg./cm.

Binder Source Binder, wt.

percent Elongation Compressive Density Percent 1 Strength Coal Tar 31274 1. 44 Goal Tar+2.5 wt. percent Vulcan 6 31 32 360 l. 45 CatalyticPetroleum Binder +2.5 Vulcan 6 31 62 383 1. 45 Minimum DesiredSpecification Optimum 60-80 320 1 43 1 High temperature flow properties.

from the group consisting of hydrogen containing cations ReferencesCited and cations of metals in Groups H, HI, 1V, V, VI-B, UNITED STATESPATENTS VIIB, VIII and the rare earth metals.

6. The process of claim 4 wherein said alumino-silicate i mp hree 2O8 55lite has been base-exchan ed with ma nesium and is 5 atch 208-83 9 g g3,140,248 7/1964 Bell et al s mlxed Wlth mamx- 3,140,251 7/1964 Plank eta1. 208

7. The process of claim 4 in which said carbon black is added in amountsof from about 2.5 to 5.0 Wt. percent. ABRAHAM RIMENS, Primary Examiner.

1. A PROCESS FOR THE PREPARATION OF BINDER OILS FROM A FEED CONSISTINGESSENTIALLY OF A DISTILLATE GAS OIL FRACTION HAVING A BOILING RANGE OFABOUT 650* TO 1150*F., WHICH CONSISTS ESSENTIALLY OF, CATALYTICALLYCRACKING SAID FEED IN A ONE-PASS CATALYTIC CRACKING ZONE, SAIDCATALYTICALLY CRACKING ZONE CONTAINING AN ALUMINO-SILICATE ZEOITE HAVINGAN AVERAGE PORE DIAMETER OF ABOUT 6 TO 15 A AND CATALYTICALLY CRACKINGSAID FEED AT A TEMPERATURE OF ABOUT 650* TO 1150*F., A PRESSURE OF FROM0 TO 500 P.S.I.G., CATALYST TO GAS OIL RATIO OF ABOUT 1:1 TO 40:1 AND ATA FLOW RATE OF 1 TO 14 W./HR./W., DISTILLING THE CATALYTICALLY CRACKEDRESULTING PRODUCT TO SEPARATE LIGHTER FRACTIONS FROM A BOTTOMS FRACTIONBOILING ABOVE ABOUT 850*F. PASSING SAID BOTTOMS FRACTION TO ADISTILLATION ZONE AND THEREIN STRIPPING SAID BOTTOMS OF SUBSTANTIALLYALL OF THE VOLATILE PRODUCTS BOILING OVER ABOUT 900*F. TO PRODUCE ABINDER OIL PRODUCT.